One example of a known portable security case is disclosed in U.S. Pat. No. 4,573,332 to Ma. The case includes two hinged sections and a cable lock that both locks the two sections together and locks the case to an immovable object. The cable lock is mounted within a bottom section of the case and includes a combination dial that protrudes through a top section of the case. One end of a cable is fixed to the lock, and the other end of the cable fits through a hole in the top section of the case before entering the lock.
Although the cable lock itself is very strong, only one of two front corners of the case is secured by the lock. The other front corner is susceptible to prying. Hinges, which are susceptible to breakage, are exposed on a back wall of the case. The cable has a fixed length that cannot be adjusted to fit more tightly around an immovable object. On the other hand, the only provision for holding the case closed before securing it to the immovable object is also the cable lock, which requires a combination to be entered before the case can be reopened.
A portable lock box is disclosed in U.S. Pat. No. 4,667,491 to Lokken et al. A tray slides within a first tubular member, and the first tubular member together with the tray slides within a second tubular member. A key lock mounted in the first tubular member includes a latch that engages a slot in the second tubular member. A cable is attached to the lock box by two knobs that are captured within the first tubular member behind slots that are closed by the second tubular member.
The three-part structure of the lock box is cumbersome to assemble and disassemble. The single key lock is the only provision for holding the case closed, and the cable is not adjustable in length.